Film cartridge



June 4, 1968 c. J. SOENKSEN ETAL 3,386,362

FILM CARTRIDGE Original Filed May 27, 1963 INVENTORS J. SoenksenChrist/an Joseph E Chin/0nd "Wu w? A ORNEYS United States Patent3,386,362 FILM CARTRIDGE Christian J. Soenksen, Mnndelein, and Joseph F.Chinlund, Northbrook, Ill., assignors to SCM Corporation, New York,N.Y., a corporation of New York Original application May 27, 1963, Ser.No. 283,409, now Patent No. 3,256,525, dated June 14, 1966. Divided andthis application Aug. 26, 1965, Ser. No. 482,845

8 Claims. (Cl. 95-31) ABSTRACT OF THE DISCLOSURE A film cartridge, for ahigh speed drum camera, with a transparent outer sleeve and a splitinternal sleeve, the normal diameter of which is larger than theinternal diameter of the outer sleeve. The split internal sleeve issprung to a smaller diameter providing a free fit insertion into theouter sleeve and also enabling disposition and pressing of a film stripbetween the internal and outer sleeves. Discs at the ends of the outersleeve enable releasable coupling and removable mounting of thecartridge coaxially on a drive spindle.

This application is a division from copending application Ser. No.283,409 filed May 27, 1963, now Patent No. 3,256,525, for High SpeedDrum Camera (Streak Photography), and the invention herein relates tothe field of photography and more particularly to a removablecombination film drum and cartridge used in apparatus for accomplishingstreak photography.

Although the concept of streak photography and the use of drum camerasto accomplish the same are old, practical utilization of drum cameras inthe art of high speed streak photography is relatively new. Existingcamera models, available today, for obtaining streak photogr-aphyrecords perform with a high degree of speed and precision. However,these drum cameras consist of intricate mechanisms and are highlydeveloped and complex instruments. They are also rather large andcumbersome.

Many cameras used in streak photography operate on the rotating prismprinciple and many others operate with a film drum; however, the drumsare constructed on a much larger scale than the present invention. Withthe present film cartridge invention for a drum camera, however, thefilm drum is very small, it is easy to load and is so inexpensive tomanufacture that many drums can be made up as pre-loaded cartridges,stored close at hand for instant use.

The use of the camera apparatus as described fully in said applicationenables concentrating a beamed light into the camera with such pinpointintensity that a very sharply defined streak is recorded on the film.The resulting record can be readily analyzed directly from a short stripof film of 35 mm. size.

The dimensions of most known drum cameras make them impractical for thesmaller projects and their extreme high cost puts them far beyond thefinancial scope of the average research laboratory. Conversely, thesimplicity of components, including the film cartridge and drum of thisinvention, and ease in operation of the camera apparatus of theinvention in said copending application result in a very low over-allcost and, coupled with small size and portability, make the cameraapparatus and the film cartridge extremely practical for laboratory orresearch use.

Accordingly, a primary object of this invention resides in the provisionof a novel low cost, compact film cartridge and drum.

Another object resides in the provision of a novel film strip drumcartridge for use "in :a high speed drum camera,

the film cartridge including a small diameter cylindrical sleeve madefrom transparent material with removable means inside the sleeve topress a strip of film against the inside cylindrical surface and endunits on both ends of the sleeve to provide for mounting of the sleevecoaxially on, and drive connection of the sleeve, to a camera drivespindle.

Further novel features and other objects of this invention will becomeapparent from the following description, discussion and the claims takenin conjunction with the drawings showing a preferred structure andembodiment, in which:

FIGURE 1 is a side elevation, partially sectioned, of the streakphotography apparatus and illustrates the relationship between the drumcamera assembly including the film cartridge drum, the light source andthe object being photographed.

FIGURE 2 is an enlarged detail section view of the film drum, assembledand mounted on the drum shaft, and also illustrates the shaft lockingdevice; and

FIGURE 3 is an exploded view of the film drum components and the drumshaft, the drum components being illustrated in the order of theirassembly.

Referring now to the drawings, in which like numerals are usedthroughout to designate like parts in the several views, and moreparticularly to FIGURE 1, the streak photography apparatus includes acamera assembly 12 and light box 52 with a base, or support structure 16as it may be used to record and measure vibrations resulting when a highspeed printer type pallet 18 undergoes an impact print action, by meansof reflected light from a polished sphere 20 mounted on the type pallet.

An upright front plate 40 is fixed to the forward end of a base plate 22and, together with a guide block 42, provides a cylindrical guide andsupport bracket for permitting reciprocal movement of the camera lenstube 44 whenever the camera is shifted on tracks 26. The rear end of thelens tube 44 projects into and is secured as by screw threads in anopening 46 in the front wall 48 of camera body 50 which in turn issecurely fastened to the subassembly base plate 24. Threadedly fastenedon the front end of the lens tube 44 is a conventional 8 mm. lens system47. Manipulation of an adjusting screw 28 will shift the complete cameraassembly either forward or backward and the barrel shaped lens tube 44will thus be concurrently shifted in the same direction along its guidebracket 40, 42, enabling focusing of the camera relative to a unit beingphotographed. Additional focusing could be accomplished, if desired, byauxiliary adjustment of the lens system 47.

A light source is used in conjunction with the camera and isincorporated in light box 52 which can be conveniently mounted on aswivel support 54 secured to the main base plate 22, as shown, or thelight box can be mounted by other means, e.g., on a conventionalindependent tripod support or on a clamp bracket, both of which devicesare well-known and commercially avail-able light source supportarrangements. The long tapered rod 62 is used where the pohtographedpart is somewhat obscured or hidden and the light beam must beaccurately directed into the interior of a machine to attain maximumreflection.

Returning to the camera assembly in FIGURES 1 and and 2, the camera body50 is a light-proof, box-like housing with a hinged top wall 76 servingas a closure and access cover to the interior of the housing 50. Shownin detail in FIGURE 2, an upright drum spindle 78 is journalled by twobearings 80 and 82, press fit into an opening 84 in the bottom wall ofcamera housing 50. A felt washer 86 may be placed on spindle 78 betweenthe two bearings and will suffice to light-proof the bearings and theirretaining Opening 84. The axis of spindle 78 is arranged to verticallyintersect the axis of the lens tube 44 with the upper portion of thespindle disposed behind the lens tube opening 46 and within the camerabody 50. Spindle 78 is axially maintained in its bearings 80 and 82 bymeans of a split ring clip 88 and the hub 90 of a small spur gear 92non-rotatably secured by a set screw on the lower end 94 of the spindle.The lower spindle end 94 is slotted at 96 thereby enabling engagement bythe blade end 98 of a spring loaded finger operated latching lever 190which is pivoted on a horizontal post 102 fixed in the base wall 104 ofcamera housing 50. The latch device 109 aids in assembly of the drum onthe spindle as will be hereinafter more fully described.

The upright wall member 34 and a cooperating horizontal wall member 108,fixed to the camera sub-assembly base plate 24, provide a bracketmounting for an electric motor 110. The motor has a downwardlyprojecting motor shaft 112 to which is secured a large spur gear 114meshed With gear 92. The large gear 114 has 3 times as many teeth asdoes gear 92 and thereby will provide spindle '78 with a 3:1 step-upratio from the rotational speed of motor drive shaft 112. Spindle '78drives a film drum 120 to be now described and its rotational speeddetermines the time base constant for the record to be made on the film.

Referring to FIGURES 2 and 3, the film drum 120 consists of four simpleparts, an outer sleeve 122, an inner split sleeve 124, and two end discs126 and 128 both of which, for convenience in manufacture, can be madeidentical although they each provide distinct structural cooperations inthe final assembly.

The outer sleeve 122 and preferably, although not necessarily the innersleeve 124 are made of a transparent material such as the aforedescribedLucite. Both end discs 126 and 128 can be made from similar plasticmaterial or from a light weight metal. In any case the discs should becoated with a flat black paint or similar substance to eliminateundesirable light rays.

Holes 132 and 134 are centrally drilled in the respective end discs 126and 128 so that they will slip over the drum shaft 78. A transverse,bayonet type lock pin 136 is fixed in the upper end of the drum shaftand, to permit discs 126 and 128 to slip onto the drum shaft, crossslots 138 and 140 are cut across the holes 132 and 134 completelythrough the respective discs 126 and 128. One disc will, but each disccan also include a second blind bottom slot transverse to the throughslots, one such blind slot 142 being shown in the upper disc 128 inFIGURE 3.

A short strip of 35 mm. film 130 is the loadin for drum 120, beingrolled into a cylindrical shape, emulsion side out, and inserted intothe outer sleeve 122. The inner split sleeve 124 is inserted into theouter sleeve by slightly squeezing the inner sleeve, closing the gap 144Where the sleeve is split to make its outside diameter small enough tofit inside of the outer sleeve and film strip. When released, the innersleeve 124 will attempt to spring back to its original diameter andeflfectively compresses the film strip 130 between the outer sleeve 122and the inner sleeve 124. A lower end disc 126 and an upper end disc 128are then placed at and spigoted into respective ends of the assembledouter and inner sleeves 32 to complete the film drum assembly 120.

An assembled film drum 120 is placed on the drum shaft 78 with the lowerend disc abutting a washer 146 which overlaps a small compression spring148 which rests on a second washer. While placing the drum assembly onand locking it to the bayonet locking pin 136, the drum shaft lockinglever 100 is held depressed, causing its end 98 to move upward into theslot 96 in the lower end of the drum shaft 78, thus preventinginadvertent rotational movement of the shaft. The complete film drumassembly 120 is forced downward against the force of the compressionspring 148 until the spindle end and locking pin 136 projects throughthe slot 140 of upper disc 12% and clears the top surface of that disc.Then the film drum assembly 120 is rotated 90 in either direction untilthe blind slot 142 is aligned with the locking pin. The film drumassembly 120 is then released and compression spring 148 forces itupward so the blind slot 142 fits over the locking pin 136, effectivelysecuring the film drum 120 for rotation with the druinshaft 78. Spring143 also helps maintain the drum components in assembly. Drum shaftlocking lever 100 can then be released and its return spring 150 willreturn it to normal position which is unlatched from the drum shaft '78.The camera housing lid 76 is closed after the drum assembly 120 isinserted.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand no restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. For use in combination in a high speed drum camera, a film strip drumcartridge comprising: a sleeve made of transparent material and havingan internal surface of cylindrical configuration, removable means havinga cylindrical configuration and extending substantially coextensive witha photographic film strip for uniformly and securely pressing the filmstrip against said internal surface of said sleeve, and means on bothends of said sleeve for enabling quick coaxial mounting and connectionof said sleeve to a drive spindle.

2. A combination cartridge and drum for a high speed rotating drumcamera for operatively maintaining a preloaded film strip in cylindricaldisposition with the emulsion side of the film strip available to recordlight directed toward the drum axis from exterior of the drum, whilerotating the drum and film strip at high speed comprising: an outersleeve made from transparent material and having an internal cylindricalsurface; an internal split sleeve normally havinga diameter larger thanthe internal cylindrical surface diameter of said outer sleeve andhaving a split enabling the inner sleeve to be sprung to a smalleddiameter providing for its free fit insertion into said outer sleeve andalso enabling disposition of a strip of film between said inner andouter sleeves; and end discs disposed over the ends of said sleeves, atleast one of which discs has a releasable drive coupling means enablinga quick release coupling of said one end disc to a drive spindle of thecamera.

3. A combination cartridge and drum as defined in claim 2, wherein saidend discs have spigot portions fitting within the ends of said internalsleeve and radially directed flange portions overlying the ends of bothsleeves, both of said end discs having means to coaxially mount saidsleeves on a spindle.

4. A combination cartridge and drum as defined in claim 2, wherein saidsplit internal sleeve extends substantially the entire length of saidouter sleeve.

5. A combination cartridge and drum as defined in claim 2, furthercomprising a spindle .and said coupling means includes a spring meansfor conjointly clamping said end discs against the ends of said outersleeve and urging said drum to its coupled condition with said spindle.

6. For use in combination in a high speed drum camera, a photographicfilm strip drum cartridge comprising: a sleeve made of transparentmaterial and having an internal surface of cylindrical configuration,means removable from within said sleeve by shifting movement relative tosaid sleeve for securely pressing substantially the entire surface areaof a strip of photographic film against said internal surface, aspindle, means at each end of said sleeve for mounting said sleevecoaxially about said spindle, and means providing for rapid connectionand disconnection between said spindle and at least one of said mountingmeans to provide for ready removal of said pressing means and the filmstrip from within said sleeve.

7. For use in combination in a high speed drum camera, a film strip drumcartridge comprising: an outer sleeve made of transparent material andhaving an internal cylindrical surface, a spindle, means for mountingsaid outer sleeve coaxially about said spindle, a removable internalsplit sleeve extending substantially coextensive with a film stripdisposed between said internal and outer sleeves for pressingsubstantially the entire surface area of the film strip against saidinternal surface, said internal split sleeve normally having a diameterlarger than the internal cylindrical surface diameter of said outersleeve and having a split enabling the internal sleeve to be 6 sprung toa smaller diameter providing for its free fit insertion into said outersleeve and also enabling disposition of the film strip between saidinternal and outer sleeves.

8. A film strip drum cartridge as defined in claim 7, including meanscomprising said mounting means and said spindle for clamping saidmounting means against the ends of said outer sleeve.

References Cited UNITED STATES PATENTS 1/1951 Chaney et a1. 346-1387/1953 Wise et a1. 346-438

